The transmission is a major component that transmits engine power and speed to the wheels upon driver's demand. Thus, the operating efficiency of the transmission or its ability to transmit maximum power with minimum losses is recognized as an essential item of transmission design and development. In an automatic transmission, for example, the efficiency of the transmission is about 85% to about 87%, which proportionately affects fuel efficiency. In a manual transmission, for example, the efficiency of the transmission is about 96% or better efficiency, which results in relatively improved fuel economy. Thus, manufacturers are looking to design an automatic transmission with an improved efficiency.
The new technology combines best of both the systems for added efficiency and enhanced fuel economy as well as automatic shifting. Manual transmission architecture with synchronizers may be used for maximum efficiency, and launch clutches, wet or dry, may be used with electronics along with mechanical or hydraulic actuation systems to effect automatic shifting.
The design of synchronizers is largely dependent upon clutch drag and transmission system efficiency: the lower the drag, the higher the efficiency, the higher the fuel economy, and the smoother the gear transition. Therefore, it may be desirable to measure the index torque of the synchronizer as designed for comparison with the drag torque to ensure that the index torque is greater than drag torque for smooth shiftability.